1. Field of the Invention
An aspect of the present invention relates to a semiconductor memory using a ferroelectric capacitor and a method for manufacturing the semiconductor memory.
2. Description of the Related Art
A ferroelectric memory using a ferroelectric capacitor is one of semiconductor memories. In a conventional process for forming the ferroelectric capacitor, a lower electrode layer, a ferroelectric film and an upper electrode layer are deposited, and the upper electrode layer, the ferroelectric film and the lower electrode layer are sequentially processed by reactive ion etching (RIE) to form the ferroelectric capacitor (for example, see T. S. Moise et al., “Demonstration of a 4 Mb, high density ferroelectric memory embedded within a 130 nm, 5 LM Cu/FSG logic process”, (U.S.A.), International Electron Devices Meeting, 2002, p. 535-538.). However, it is hard to vertically process sidewalls of the upper electrode layer, the ferroelectric film and the lower electrode layer by the RIE. In some cases, moreover, a fence is formed when the sidewalls are vertically processed. For this reason, an RIE converting difference for preventing the formation of the fence is required. When the upper electrode layer, the ferroelectric film and the lower electrode layer are processed by taking into account the RIE converting difference, an interval between ferroelectric capacitors which are adjacent to each other is enlarged. Therefore, for an equal cell size, it is hard to increase an area of the capacitor sequentially processed by the RIE.